The effect of p53-function on the sensitivity to paclitaxel with or without hyperthermia in human colorectal carcinoma cells.

The importance of p53-function for the sensitivity to paclitaxel with and without hyperthermia (HT) was studied in an isogenic cell line system. The inactivation of p53 decreased sensitivity to paclitaxel (1.1-2.5-fold), which correlated with a lower induction of apoptosis. The magnitude of the G2/M arrest after treatment with paclitaxel was similar in all cell lines. The cytotoxicity of paclitaxel was not enhanced by HT in either wild-type p53 or p53-inactivated cells. In conclusion, cellular sensitivity to paclitaxel depends on p53-function by its ability to induce apoptosis. Irrespective of the p53-function HT was not able to enhance the sensitivity to paclitaxel.